Head-to-Head: Williams lead 7-1

Centre Court is not the squared circle, but Victoria Azarenka's last trip inside the lines with Serena Williams at a major left her feeling like she'd spent a few rounds on the ropes.

"It's painful. To have somebody just going at you like that, it's a little bit painful," Azarenka said after Williams roared out to a 5-0 lead en route to a 6-1, 7-6 (5) U.S. Open third-round victory last September.

When the Grand Slam champions face off for a spot in Saturday's Wimbledon final, four-time champ Serena will be favored, and rightfully so. But the second-ranked Azarenka will have more than a puncher's chance of pulling the upset and advancing to her first final at The Championships.

The 13-time Grand Slam champion's superior serve and speed give her an authoritative edge in this match-up, which she has dominated. Serena has won seven of their eight career meetings, with her lone loss coming in the 2009 Miami final, but this is a more confident and complete Azarenka than the player who Williams beat in New York 10 months ago. The aggressive baseliner from Belarus has won four of her nine prior tournaments this season, including her first major in Melbourne, and sports a 43-4 record. It even has Serena spinning her as the favorite.

"If Victoria wins, she's had a better year than I have," Williams said. "Going against a player like that, I feel like she almost has an advantage, I guess. So that makes me really relaxed and I can just kind of hit."

It's a wise mindset as Serena, one of the best closers in the Open era, has looked tight at times in this fortnight and in recent major losses, to Samantha Stosur (2011 U.S. Open, final), 56th-ranked Ekaterina Makarova (2012 Australian Open, fourth round) and to 111th-ranked Virginie Razzano (2012 French Open, first round). Williams' forehand return hasn't been at its peak, though she is coming off her best match of the tournament—a 13-ace, 6-3, 7-5 sweep of reigning champion Petra Kvitova—and she's had plenty of practice in refining her return while playing doubles with sister Venus.

This is an interesting match because Serena, whose serve, power, and speed are key components, owns a game-changing backhand, which she often whips cross-court to break open rallies. Azarenka's two-hander is one of the most dangerous shots in women's tennis, too, so whomever wins the backhand-to-backhand exchanges will hold a big advantage. If Williams is occasionally driving her backhand down the line and playing the dipping, short-angled cross-court backhand, that's a sign of confidence and warning sign for Azarenka.

Perhaps the best benefit Vika can draw from their head-to-head history is, it's all in the past. Serena has won their last five encounters and all five of their major matches, but that's meaningless if Azarenka can press the reset button and play with the precision and power she's shown in deconstructing opponents' defense—a tall order, of course, but she's surrendered just 23 games in reaching the final four.

"Obviously she's a great fighter. She never gives up," Azarenka said of Williams. "She has a huge serve, which we all know ... I don't really like to look back in history because every time you step on the court it's a new story. You kind of write your own history every time."

Throughout this season, Azarenka has been the more consistent player, but Williams is the more explosive one. While Azarenka possesses a dangerous return game—she's averaging five breaks per match in the tournament—Serena leads the tournament by a considerable margin in aces (61), owns the all-time Wimbledon record for most aces in a fortnight (89), and has only dropped serve five times in five wins. Vika can be a sniper guarding the baseline, but Serena's strength on serve, her past success against Azarenka, and the fact she is 9-0 vs. Top 5 players in the past year makes her the pick.

The Pick: Williams in three sets

For a preview of the Radwanska vs. Kerber semifinal, click here.